Nutrition and Nutrients in the Diet

1 Nutritional significance of protein

(1) Protein is an important component of the human body (about 16%-19% of the body weight,ARA about 3% of the protein is metabolized every day), all the cellular tissues of the human body are composed of protein;

(2) is adjusted as well as a variety of different physiological systems function with indispensable substances such as enzymes, hormones, hemoglobin,DHA myofibrillar coagulation proteins, collagen and antibodies to carry out protein;

(3) the acid-base balance in the human body,β-carotene the distribution of water in the body, the transmission of genetic information and the transportation of many important substances are related to proteins;.

(4) protein is the main source of nitrogen in the human body, the human body consumes a portion of the daily energy from protein.

2. The nutritional significance of fat

(1) to provide collective energy, 1g fat can provide 37.7 kj (9 kcal) of energy.

(2) It is an important part of human tissue and plays an important role in maintaining cellular outcome and function;

(3) It prolongs gastric emptying and increases can feeling of satiety;

(4) It can improve the sensory properties of food, increase appetite, and promote the digestion and absorption of nutrients.

(5) It is one of the important sources of fat-soluble vitamins, such as vitamins A, D, E and K...

3. Physiological significance of carbohydrates

Carbohydrates can be categorized into different monosaccharides, disaccharides and polysaccharides. Their physiological significance for research:

(1) It is the most economically developed and primary source of great energy for most other people in the world;

(2) It is an important component of living organisms such as cell membrane glycoproteins, connective tissue mucins, nerve tissue glycolipids, ribose and deoxyribose (RNA and DNA) involved in the transmission of genetic information;.

(3) Liver protection and detoxification;

(4) adequate carbohydrates save protein consumption

(5) anti-ketogenic effect, insufficient carbohydrate intake, incomplete fat oxidation, excessive ketone bodies.

4. The physiological research significance of dietary structural fiber

Composition of dietary fiber: cellulose, hemicellulose, lignin, pectin and some with cellulose binding and can not use lipids and nitrogen. Physiological effects: Promote intestinal peristalsis, improve intestinal flora, regulate blood sugar, lipid metabolism, anti-cancer. Cereals, tubers, roots, vegetables and fruits are the main sources of dietary fiber.

5. Physiological significance of inorganic salts

(1) Important components of human tissues, such as calcium, phosphorus and magnesium in bones and teeth, and iron in hemoglobin;

(2) in intracellular and extracellular fluid, inorganic elements and proteins together to regulate cell membrane permeability, control water, maintain normal osmotic pressure, maintain acid-base balance (acidic elements of chlorine, sulfur and phosphorus, alkaline elements of sodium, potassium and magnesium), maintain neuromuscular excitability;.

(3) constitute auxiliary groups of enzymes, hormones, vitamins, proteins and nucleic acids, or involved in the activation of enzyme systems.

6. Physiological significance of vitamins

Vitamins are a large group of substances with varying chemical knowledge structure and functional requirements of physiological systems. But between them are a natural presence in food, the human body can not meet the normal use of synthesis, the need is very small, each has a special student physiological education function, neither can participate in the important composition of the social organism nor to provide a kind of energy of the organic combination of substances, according to its solubility is divided into fat-soluble vitamins and who soluble vitamins of two major categories. Fat-soluble vitamins: such as vitamins A, D, E, K. Water-soluble vitamins: such as B, C and so on.

(1) Physiological functions of vitamin A: Promote the development of bones, maintain the health of epithelial tissues, participate in the formation of retinal retinal retinol, as well as participate in the structure and function of the membrane. The best food sources are various animal livers and cod liver oil.

(2) Physiological functions of vitamin D: regulating calcium and phosphorus metabolism, promoting calcium and phosphorus absorption and utilization. The best food sources are cod liver oil, animal liver and egg yolk.

(3)The physiological function of vitamin E is mainly antioxidant, mainly found in vegetable oil.

(4) Physiological functions of vitamin B1: to form decarboxylase enzyme to participate in sugar metabolism; to promote the synthesis of acetylcholine and inhibit the decomposition of acetylcholine. Vitamin B1 is widely found in natural foods and is abundant in cereals, legumes and dried fruits.

(5) Vitamin B2's physiological system function: constitutes the cofactor component of many enzyme systems in the body, and is directly involved in learning the biological oxidation reaction process. General animal food technology content has a high.

(6) Vitamin C: 1 Physiological function in the body, together with other antioxidants can scavenge free radicals. Maintains the activity of proline hydroxylase and iron in lysine hydroxylase. Converts cholesterol to sulfate, participates in hydroxylation of cholesterol in the liver, forms bile acids, and lowers blood cholesterol levels. Vitamin C comes mainly from fresh vegetables and fruits.

(7)Physiological functions of niacin:Niacin, also known as nicotinic acid, is a component of coenzyme I and coenzyme II, and is a donor and acceptor of hydrogen in oxidation reactions. It is involved in intracellular respiration, in the synthesis of fats, proteins and DNA, and plays an important role in the synthesis of sterols to reduce cholesterol levels in the body. It is found in both animal and plant foods.

vitamins Physiological protein

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